A solenoid valve is used for controlling a supply and its stop of compressed air to a pneumatic apparatus such as a pneumatic cylinder or for controlling a pneumatic circuit such as selection or switch of the pneumatic circuit. The solenoid valve includes a pilot-controlled type. This pilot-controlled type comprises: a main valve shaft for switching an output port communicating with the pneumatic apparatus by switching a position of being caused to communicate with a supply port communicating with a compressed air source and a position of being caused to communicate with an exhaust port for exhausting compressed air to the outside; and a pilot-controlled solenoid valve which supplies, to the main valve shaft, pilot pressure for driving axially the main valve shaft, whereby those members constitutes an solenoid valve assembly.
The solenoid valve manifold, in which the plurality of solenoid valve assemblies are collectively attached to a supporting member, includes a monoblock type and a split type. In the monoblock type, the plurality of solenoid valve assemblies are attached to a manifold block in which a common supply path and a common exhaust path are formed and which serves as a supporting member. The split type is also called a divided type, and includes a type in which the plurality of solenoid valve assemblies stacked are fixed by a rail-like supporting member, i.e., a DIN rail, and a type in which the plurality of solenoid valve assemblies stacked are fixed by a tie rod. In the split type, by the solenoid valve assembles which are in a stacked state, supply holes formed in the respective solenoid valve assemblies are continuous to form the common supply path, and exhaust holes are continuous to form the common exhaust path. Patent Document 1 discloses a solenoid valve manifold of the monoblock type, and Patent Document 2 discloses a solenoid valve manifold of the split type. Also, FIG. 1 in Patent Document 3 describes the plurality of solenoid valves stacked.    Patent Document 1: Japanese Patent Application Laid-Open Publication No. 2003-301986    Patent Document 2: Japanese Patent Application Laid-Open Publication No. 11-63348    Patent Document 3: Japanese Patent Application Laid-Open Publication No. 2-163579